1. Technical Field
The present invention relates to an apparatus of driving wheels for an in-wheel system.
2. Description of the Related Art
A hybrid vehicle, a fuel cell vehicle, an electric vehicle, and the like have emerged as an alternative of a known vehicle having a gasoline engine or a diesel engine using fossil fuel. The hybrid vehicle uses both power generated from an internal combustion engine and power generated from an electric motor, while the electric vehicle uses only power generated from the electric motor driven by electric energy of a battery and the fuel cell vehicle uses only power generated from an electric motor driven by electric energy produced from hydrogen.
The in-wheel system as a system in which the electric motor is mounted in not an engine room but wheels and driving force is controlled directly in each wheel is used in the vehicles such as the hybrid vehicle, the fuel cell vehicle, and the electric vehicle using the electric motor as a driving source of the wheel.
The in-wheel system is a system in which a motor is installed in the wheel and power of the motor is transferred directly to the wheel. Various types are provided according to an implementation method and the in-wheel system is classified into a basic type in which only a driving motor is mounted in the wheel to coexist with an existing suspension system which is called a simple in-wheel system and an integrated in-wheel system in which all of brake, steering, suspension systems are mounted in the wheel together with the driving motor.
The simple in-wheel system may be classified into an inner rotor type and an outer rotor type again according to relative positions of a stator and a rotor.
The in-wheel system brings a big change in a vehicle design method and an assembly line. That is, when the in-wheel system is adopted, shapes and functions of engine peripheral parts such as a sub-frame, a vehicle body, and the like supporting an engine based on the engine room will be drastically changed and designed. Further, an in-wheel module manufactured as a module to be mounted in the wheel can be switched to a type that sequentially supplies and assemblies an in-wheel module having an output required by a consumer in a vehicle sub-assembly line. Therefore, an engine driving system which is a core technology of the vehicle is manufactured outside through the in-wheel module to be assembly to the vehicle. From the point of view of a vehicle manufacturer, since the vehicle manufacturer can cooperate with part suppliers by laying emphasis on overall performance objectives and designs of the vehicle, a development cost can be saved and a development risk can be distributed.
However, there is a structural problem for supporting a load because the wheel and the motor are inclined in only one direction of a fixation supporter by adopting the known in-wheel system. Further, driving reliability of the in-wheel system is deteriorated due to the problem to thereby exerting a fatal influence on the driving performance and reliability of the vehicle adopting the in-wheel system.